Guide to API Security in the IoT Age

From smart homes to wearable devices to connected cars, the Internet of Things (IoT) is bringing about a new era of hyper-connectivity. Experts expect investments in the IoT ecosystem to rise above $1 trillion in 2026 — with no signs of slowing down. Application programming interfaces (APIs) are the backbone of IoT, ensuring scalability and security across billions of connected devices.

But because any internet-connected device is an entry point to a larger network, the sheer scale of the IoT comes with cybersecurity risks. API security is necessary to properly secure IoT devices and protect data during the transmission process, allowing access only to authorized devices and detecting potential threats to the API.

Read on to learn how to build a comprehensive IoT API security strategy to protect devices in IoT deployments.

Understanding the role of APIs in IoT

Application programming interfaces (APIs) are a set of protocols, tools, and definitions used to build and integrate application software. They allow different applications to communicate with each other through data sharing, without transferring foundational code or architecture.

APIs can be public or private depending on whether they need to be accessible to developers outside an organization or limited internally to connect different systems, software, etc. These functionalities encourage data management and analysis, making it easier for developers to build new software applications. 

In IoT deployment, a remote API connects to the IoT device. The API then transfers data from the connected device to an application, platform, or server to make a request. Conversely, APIs can also instruct the connected device to carry out an action or a set of actions.

APIs are the foundational tools that enable software to remotely access IoT devices around the world — but how does the communication between IoT devices and servers actually work?

• They promote discoverability. APIs support seamless device detection and onboarding to bring IoT devices onto networks. For example, devices can send out discoverability data that APIs immediately recognize.
• They provide a standard architecture. APIs provide a routine set of protocols and tools that IoT devices and servers use to exchange data without the need for underlying code. This process improves both the effectiveness and reliability of the interaction.
• They facilitate data transmission. Through APIs, IoT devices send data to the appropriate cloud server or platform to ingest, analyze, and store it instantly.
• They allow control signals. APIs let applications and servers send signals to IoT devices so that they execute a set of actions, such as answering a user’s question or turning on their car.

Unique API security challenges in IoT

Every IoT device is vulnerable to cyberattacks, meaning that lazy or ineffective API security measures may quickly expand the attack surface. Attackers can mine sensitive data, such as customer financial details, contact information, or company trade secrets, from these IoT devices — creating a unique set of circumstances for API security.

The distribution of IoT introduces several security complexities, especially as it relates to scalability. APIs must be capable of securing billions of devices across different types of infrastructure while accommodating resource-limited IoT endpoints.

Additionally, APIs must provide end-to-end data protection for sensitive data traveling from the device to the server and back — which can be precarious with multiple layers of security concerns related to devices, network, and cloud connectivity.

Lastly, time-sensitive IoT applications, such as autonomous vehicles or wearable medical devices, require instant and accurate data responses that can distract from overall security. 

Scalability

To successfully deploy IoT, companies need to be able to scale their cloud and infrastructure up and down with the data provided by their collection of devices. IoT comprises both software and hardware, so building a connected user experience can get tricky. An IoT deployment needs multiple layers of scalability that can accommodate varying networks, designs, and requirements. 

Scalability is crucial for providers operating in IoT because, without powerful connectivity, device management, and web development, there are elevated risks of project failure.

With more connected devices comes more attack surfaces; bots can locate vulnerabilities in devices and target entire servers through DDoS attacks, making a solid API security strategy imperative for deploying IoT products at scale.

Want to learn more about the importance of the right strategy in your approach to API security? Check out the Becoming a Secure API-First Company eBook for insights from Marco Palladino, Kong Co-Founder and Chief Technology Officer.

Device diversity 

IoT ecosystems are massive, with a broad diversity of devices and formats that can make it difficult to integrate, analyze, and secure the data. When an IoT provider doesn’t implement tight security standards and requirements for all device types, it can create room for error.

Managing these IoT devices is yet another challenging obstacle because servers need to quickly load new features and security updates onto different hardware and software designs when they discover vulnerabilities. If companies cannot integrate varied hardware infrastructure with cloud software and connectivity providers, they may not be able to protect all connected devices in a timely manner.

Real-time requirements

Some IoT devices have real-time requirements that need to be completed by APIs within a specified period. If data returned for real-time requirement requests is inaccurate, there can be potentially catastrophic consequences. IoT providers may compromise security to improve API performance for these requests, but such operational errors can bring down the entire system.

APIs must keep each real-time requirement separate, or they can interfere with one another and compromise the whole network if one fails.

In the IoT environment, APIs often connect with automated equipment, monitoring systems, and other APIs to complete real-time requirements, meaning that all of these communications need airtight security to prevent code injection attacks, priority inversion bugs, and other threats.

Essential API security measures for IoT

It's important to consider API designn, as poorly designed APIs make your IoT data an attractive target for attackers.

One of the best tools to add to your IoT API security arsenal is an API gateway, which acts as a single entry point for interactions between IoT devices and cloud-based services. API gateways provide a standardized way to access and control devices and securely manage data flows, making them an invaluable asset to IoT providers.

Let’s take a closer look at a few of the major IoT security measures that development teams should consider implementing.

Authentication

IoT devices require a strong authentication infrastructure — though many currently have little to no authentication protocols. Passwords aren't enough because they can be stored in an application’s source code, making them publicly available. Attackers can access an entire server through stolen passwords or use a bot to administer malware or DDoS attacks.

IoT providers should make their ecosystem more secure by requiring multiple authentication steps, using API keys, and creating a stronger default password baseline to help control the data that IoT devices transmit to their APIs.

Encryption

Another non-negotiable step to ensure IoT API security is data encryption, because it helps prevent attackers from accessing, manipulating, or stealing sensitive information. Data encryption creates undecipherable data with SSL (Secure Sockets Layer) or TLS (Transport Layer Security) protocols, protecting data in transit and at rest.

Developers should consider using an API gateway in conjunction with encryption and access controls to better protect both IoT devices and cloud servers from external threats.

Secure Coding 

Of course, implementing a secure set of coding practices is an advisable strategy for development teams, too. Securely coded gateways reduce the attack surface and blast radius by limiting lateral mobility in the event of an attack. Similarly, they minimize vulnerabilities that could lead to injection attacks or access control issues.

A quality API gateway has bulletproof infrastructure, up-to-date software, and a solid security network.

Securing IoT data with APIs

To secure IoT data in transit, APIs mandate encryption protocols for all data that moves between IoT devices and servers.

Additionally, APIs implement access controls in their interfaces, selectively restricting access to authorized applications or users. This strategy works alongside robust authentication techniques, such as API tokens or keys, which ensure safe access and prevent man-in-the-middle attacks. 

For data at rest, APIs require databases to use encryption for data store protection. By pairing encryption with secure coding practices like input validation and key rotation, developers can prevent data at rest from being compromised. APIs can also anonymize restful IoT data fields to provide privacy while maintaining access logs to monitor behavior patterns for early threat detection.

There are data privacy and compliance concerns to keep in mind when using IoT. IoT systems and providers may be subject to regulations like GDPR or CCPA when collecting data from devices. Providers must also comply with data protection, privacy, and security rules that may require them to obtain consent when collecting, processing, and storing personal data through IoT devices.

The more transparency with users, the better — which is why providers should establish clear data handling protocols and privacy policies from the get-go. Any provider that does not comply with compliance regulations or privacy requirements could face legal consequences that derail their IoT deployments entirely.

Examples of API security practices in IoT

API security is involved in every aspect of IoT deployment, including activating and deactivating devices, preventing fraud through alerts, enforcing data usage limits, and more. 

API security strategies protect IoT data from external attackers beyond just encryption. For example, if an API is vulnerable, attackers can engineer it to return a user’s information when they use the IoT device — which can eventually lead to DDoS attacks.

An API-aware web application firewall (WAF) is useful in this case because it can protect IoT devices by filtering and monitoring traffic between the device and the internet. This tactic also helps developers detect malicious threats and respond to them quickly in the event of a data breach. 

Without APIs to connect devices and servers, it would be impossible to efficiently deploy IoT products at scale. With that being said, APIs also come with a specific set of risks that can impact IoT security, and API development teams should test APIs used in IoT deployments for vulnerabilities.

A robust API management solution can help identify and mitigate vulnerabilities in your APIs so you can scale IoT products smoothly.

The future of API security in IoT

API security will need to evolve alongside the IoT ecosystem, and there are a few key emerging trends and technologies that will shape its future. 

AI and machine learning

AI and machine learning offer exciting advancements for IoT API security. Machine learning models provide intelligent, real-time threat detection for APIs by performing security analysis from structured and unstructured data sources. These models can identify suspicious IP addresses, abnormalities in API traffic, and unusual server logs to flag suspicious activities or behaviors.

Machine learning will further streamline security analysis to accommodate the time-sensitive nature of IoT deployments, enabling continuous risk assessment, critical decision-making, and improved security insights. 

Blockchain

Blockchain is a resilient system that limits data access by default, and it is highly secure — giving it a bright future in API security. Blockchain technology acts as a kind of encrypted data storage that can strengthen API security from the ground up, and its decentralized networks establish trust in digital identities, making it a difficult target for malicious attacks.

Blockchain requires some form of digital identity to post a transaction ledger, but it can mask those identities to help create access control and identity management for APIs involved in IoT deployments. This technique presents the possibility of embedded security for all IoT devices. 

Zero Trust architecture

The Zero Trust API security model is gaining traction because it operates on the belief that organizations should not automatically trust any entity attempting to access a network.

Traditional security models assume that all entities within an organization are trustworthy, but Zero Trust always verifies these entities before granting them access to data or networks. This model is increasingly relevant for IoT API security because APIs often handle sensitive data and IoT connectivity — meaning that every API request must be authenticated, authorized, and validated for proactive protection.

Conclusion 

There’s no question that organizations need a bulletproof API security strategy to protect APIs powering the IoT ecosystem. Devices that are connected to the internet will always carry some level of risk, but strong authentication, encryption, and coding techniques can prevent malicious attacks.

The best way to strengthen your API security strategy is to use an API gateway solution that identifies threats and proactively squashes them. Kong’s cloud-native API platform offers robust authentication mechanisms and secure data transmission for built-in, end-to-end security — so you can scale more and worry less.

Ready to learn more? Request a demo today.